The present invention relates to a jig to be mounted on the work fixing member of a machine tool utilizing a mount bore formed in a work fixing surface of the fixing member for use in fixing work to the fixing member by work fixing means.
Work is fixed to a work fixing surface of a table (work fixing member) of a machine tool conventionally, for example, by an arrangement shown in FIG. 5. With reference to FIG. 5, a table 1 has a plurality of threaded bores 2 extending from a flat upper surface 1a (work fixing surface) thereof to a flat lower surface 1b thereof. A jig main body 3 in the form of a vertical rod and having screw portions 3a, 3b at respective opposite ends thereof has its lower screw portion 3a screwed in the threaded bore 2 at a suitable position and is fixed to the table 1 with a lock nut 4 screwed on the screw portion 3a. A clamp 5 for fixing work W has a threaded bore 5a at a base end thereof and a through bore 5b at an intermediate portion of the length thereof. An adjusting bolt 6 is screwed in the threaded bore 5a from below, and the upper screw portion 3b of the jig main body 3 loosely extends through the bore 5b. The adjusting bolt 6 has a head 6a having a convex lower face. The head 6a rests on a concave seat 7 having a concave upper face and provided on the table 1. The clamp 5, adjusting bolt 6 and concave seat 7 provide work fixing means. The work W is fixed to the upper surface 1a of the table 1 by placing a forward end of the clamp 5 on the work W as positioned in place on the table 1 and screwing a clamp nut 8 on the upper threaded portion 3b of the jig main body 3. The work fixing means comprises the clamp 5, adjusting bolt 6, concave seat 7 and clamp nut 8.
However, in the case where the work W is to be fixed to the upper surface 1a of the table 1 as shown in FIG. 5, the lower screw portion 3b of the jig main body 3 must be screwed into the threaded bore 2 to a controlled depth by a cumbersome procedure, and a tool is necessary for screwing the lower screw portion 3b of the jig main body 3 into the threaded bore 2. Fixing the jig main body 3 to the table 1 therefore requires much time and labor, hence the problem that the overall procedure for fixing the work W is cumbersome.
An object of the present invention is to solve the above problem and to provide a work fixing jig for machine tools by which work can be fixed to the tool more easily than conventionally.
The present invention provides a work fixing jig for machine tools which is to be attached to a work fixing member of the machine tool utilizing a mount bore formed in a work fixing surface of the fixing member for use in fixing work to the fixing member by work fixing means, the jig comprising a jig main body having a contact surface to be brought into intimate contact with the work fixing surface, an engaging member projecting from the contact surface of the jig main body and insertable into the mount bore of the fixing member, the engaging member having an engaging portion releasably engageable with a portion of the fixing member defining an opening of the mount bore opposite to the work fixing surface, a rod movable in directions orthogonal to the contact surface relative to the jig main body, disengaging means provided between the engaging member and the rod for engaging the engaging portion of the engaging member with the opening-defining portion and disengaging the engaging portion from the opening-defining portion by the axial movement of the rod, biasing means provided between the jig main body and the rod for biasing the rod into the engaging movement, and a fluid pressure cylinder provided between the jig main body and the rod for bringing the rod into the disengaging movement against the biasing force of the biasing means.
The term the xe2x80x9cmount borexe2x80x9d used above is to be interpreted as including a mount groove.
The work fixing jig of the invention for machine tools is used in the following manner for fixing work in place. A fluid is supplied to one of the fluid compartments of the fluid pressure cylinder to move the rod for disengagement against the biasing force of the biasing means to release the engaging portion of the engaging member from an engaged state. In this state, the engaging member is fitted into the mount bore of the work fixing member. The pressure fluid is then discharged from the fluid compartment of the cylinder, permitting the biasing force of the biasing means to bring the rod into the engaging movement, whereby the engaging portion of the engaging member is brought into engagement with the opening-defining portion of the work fixing member. In this way, the jig main body is fixed to the fixing member for the work fixing means to fix the work in position.
The contact surface of the jig main body is brought into intimate contact with the work fixing surface of the fixing member, whereby the depth to which the engaging member is fitted into the mount bore of the fixing member is determined in accordance with the depth of the mount bore and the length of the engaging member. This eliminates the need to control the depth of fitting. Unlike the conventional case wherein the screw portion of the jig main body is screwed into the threaded bore in fixing the jig main body to the work fixing member, the jig main body of the invention can be fixed to the work fixing member without necessitating any cumbersome procedure. The overall work fixing procedure can therefore be made more simplified than when the conventional jig is used.
The work fixing jig of the invention for machine tools may be so adapted that the engaging member is generally in the form of a hollow cylinder and provided at a forward end portion thereof with the engaging portion engageable with the opening-defining portion of the work fixing member, the end portion providing the engaging portion being diametrically contractable or expandable, the engaging portion being engageable with the opening-defining portion of the work fixing member when said end portion providing the engaging portion is diametrically expanded, the engaging portion being disengageable from the opening-defining portion when said end portion is diametrically contracted, the engaging member having an elastic ring fitted therearound for diametrically contracting said end portion, the rod being inserted through the engaging member, the rod having a large-diameter portion for diametrically expanding said end portion when positioned inside the engaging member, the large-diameter portion permitting said end portion of the engaging member to be diametrically contracted by the elastic force of the elastic ring when moving out of the engaging member.
In this case, the engaging member and the disengaging means become relatively simple in construction.